Before a detailed discussion of this new electronic approach to slot car control is pursued, it is necessary to consider the prior art. In this way, it will become clear that the electronic controller, and the concepts it embodies, are new and unique to slot car control. The prior art embodied the use of a large wire-wound resistor that had a sliding-contact means of varying the resistance and thus the amount of current supplied to a slot car. The variable resistance is placed in series in the current path between a DC source and the track on and in which the slot car rides. Either a thumb-operated plunger or a finger-operated trigger is used to vary the resistance of the controller in order to vary the speed of the slot car. This prior art design has two main deficiencies. First, the large resistor gets very hot in use and will very frequently burn open. This requires replacement. Many elaborate schemes have been devised employing heat sinks to remove heat quickly and spare the resistor. Second, a different amount of resistance is needed to accommodate different types and classes of slot cars. These resistors range from 60 or so ohms down to less than 1 ohm of resistance. It is not uncommon for an individual to have several controllers to match different slot cars. The new design by Mark E. Hazen does not get noticeably hot and can quickly be programmed to match any car, or person's tastes, by simply replacing a "personality module".